1. Field of the Invention
The present invention relates to an electrophotographic belt used as an intermediate transfer belt or the like of an electrophotographic image forming apparatus, and also relates to an electrophotographic image forming apparatus.
2. Description of the Related Art
An electrophotographic image forming apparatus uses, for example, an intermediate transfer belt which is used for carrying, on a surface thereof, toner images having been primarily transferred from electrophotographic photoconductive members and transporting the toner images to a secondary transfer region where the toner images are transferred to a transfer medium such as paper, or a transfer-transport belt which is used for carrying, on a surface thereof, a transfer medium such as paper, onto which a toner image is transferred and transporting the transfer medium. An electrophotographic belt used as such members is required to have electroconductivity according to the use of the electrophotographic belt. For the purpose, an electrophotographic belt to which electroconductivity is provided by producing the belt in such a manner that an electrolyte is dispersed in a binder resin has been proposed and utilized. In the electrophotographic belt to which electroconductivity is provided by incorporation of an electrolyte, however, the electrolyte or ions generated by dissociation of the electrolyte may gradually migrate toward the surface of the belt (this phenomenon is hereinafter referred to as “bleeding”) as a result of applying a DC bias to the belt within the electrophotographic image forming apparatus (herein, an electrolyte and ions generated by dissociation of the electrolyte may be collectively referred to as “electrolyte”).
The bleeding of the electrolyte may cause the electroconductivity of the electrophotographic belt to change with time. If the electrophotographic belt is used as an intermediate transfer belt, the electrolyte deposited on the surface as a result of the bleeding may affect the efficiencies of the primary transfer and the secondary transfer of toner images. Accordingly, Japanese Patent Application Laid-open No. 2010-139650 has proposed that hydrotalcite is added as a filler for suppressing the bleeding of an electrolyte.